As an emotional Thomas Bach left the stage in Buenos Aires having become just the ninth president of the International Olympic Committee in its 119-year history, a phone was thrust into his hand.

On the other end was Vladimir Putin, the first in a queue of world leaders to deliver congratulations that underlined the importance of a role described as the most powerful in sport, within an organisation that is increasingly the forum for a brand of soft diplomacy that goes way beyond the field of play.

The former fencer, unknown to most sports fans but an influential figure in German sport and business, takes over when the Olympic movement is at a crossroads.

Bach, 59, a gold medallist at the 1976 Olympics in the team foil, has spent much of his post-athletics life building the sort of CV and contacts that left him ideally positioned to ascend to the presidency but have also prompted claims of a conflict of interests.

Bach was already a promising fencer at the age of five when his parents forced him into the sport against his will (he preferred football). At 22, he won the gold medal.

By then he was already thinking beyond fencing. He has said his involvement in sports politics was driven by the West German government's decision to boycott the Moscow Games in 1980.

The following year he and Seb Coe became the first athletes to address the IOC Congress. A decade later he was elected an IOC member at the age of 37 and he has since played a series of influential roles within the organisation.

Alongside his rise to prominence within the IOC and German sports administration, Bach took a series of powerful positions in business including a spell as an Adidas executive and a consultant to Siemens, prompting claims of a conflict of interest.

Throughout the controversial latter days of the reign of Juan Antonio Samaranch as IOC president, which ended in 2001 when he was succeeded by Jacques Rogge, Bach was seen as one of his proteges.

A German TV documentary aired in the days before the vote compiled a number of claims against Bach, including allegations that as part of Adidas chief Horst Dassler's "inner circle" he helped place favoured candidates in sporting federations and paid inducements to sports stars.

The documentary featured allegations that he had cheated as a young fencer by using a wet glove to fool the electronic scoring system and claimed the Arab-German Chamber of Commerce and Industry, of which he is president, is anti-Israeli.

Bach dismissed the claims as nonsense and "without substance" and the claims, some old and some new, were not backed up by a smoking gun. "He is always standing next to a broken window but no one has ever seen him throw the stone," one of Bach's detractors in Buenos Aires said.

According to Der Spiegel, in 2005 Bach had a consultancy contract with Siemens for around €200,000 and allegedly tried to use his IOC connections to attract Kuwait as a large-scale investor for a Siemens project. It was suggested he had lobbied Sheikh Ahmed al-Sabah, then Kuwaiti energy minister and an IOC member, on behalf of Siemens.

Bach denied the allegations, claiming his business activities and his "honorary positions in sport" were separate.

Bach's cause in the presidential campaign was indisputably helped by the support of al-Sabah, now head of the Association of National Olympic Committees. The Kuwaiti admitted openly lobbying for Bach, a breach of IOC rules, but both downplayed his influence following Bach's victory.

Yet one of his rivals for the presidency, the Swiss lawyer Denis Oswald, said he did not "share the same values" as Bach.

"I want an independent candidate who is not dependent on certain alliances and who uses his position for nothing else than the good of sport," said Oswald.

For every detractor, Bach − who insisted he was beholden to no one − has many supporters. British Olympic Association chairman Coe called him "a perfect choice for the movement, for athletes and for sport".

Bach can expect his past to be re-examined by the German media, and in particular by specialists such as Jens Weinreich, in light of his victory. But he has enough on his plate dealing with the present.

In addition to political challenges at next year's winter Olympics in Sochi, there is concern over the chaotic preparations for the 2016 summer Games in Rio and fears that the size and cost of the event is getting out of hand.

Not to mention the battle against doping and the growing threat of illegal betting.

None of which prevented Bach from radiating intense satisfaction at landing the job, likening it to conducting an orchestra. Keeping them in tune will be a challenge he has been preparing for most of his life.